Pump jack



R. T. CRUIKSHANK PUMP J ACK July 13, 1948.

Filed March 1, 1946 FIG.2

FIG. 5

INVHVTOR. ROSS T. CRUIKSHANK BY I ATTOKAZ'YS Patented July 13, 1948 UN IT ED" STATES PATIEN T OFFICE PUMP JACK jRoss T.,Cruikshank, Minneapolis, Minn, assignor,;-bydirectandmesne assignments, of forty- .fiveper-centtoCarl A. Anderson, Minneapolis,

Minn., andten per cent to Louis Wigen ApplicatiomMarch 1, 1946, Serial No. 651,359

6--Glaims. .1

This invention relates-topower.jacks-fonlcngitudinally reciprocating. av pumpplunger or the like through application of either" rotary or. oscillatory power.

It is anobject of the inventionv toprovide a simple, compact and highly efiicient pump jack or the like, driven from a. source of .rotary or oscillatory power .andoperativet-o apply straight lineforces on1y,longitudinal1y f, the reciprocable driven member.

A further object is the provision of a power jack ofthe class described for reciprocatingpiston rods and the like, whereby power is applied in both; pulling andthrust strokes upon thereciprocable member in an even manner with the elimination of jerkiness :and sharp; pulsations.

, the several views and in ,Which 1 Fig. 1 isa front elevation of an: em-bodiment of the inventionyapplied to ;a verticalpump rod showing the working partsin the extreme elevated positionofthepump rod;

Fi .2 is a similar view showing thepositioning of the parts'in the intermediate position-ofthe stroke of the pump rod;

Fig. 3 is a similar viewshowing the: parts positioned with the pump rod at the lower endof its stroke;

Fig. 4 is a side. elevation showing themechanism positioned at the top of the pumping stroke; and

. Fig. 5 isa cross section taken on the line,55 of Fi '2.

In the form of theinvention ,illustrated,.- the mechanism is mounted upon asuitable base I, as shown,v comprising acap, or head internally threaded to fit and besecuredto the diminished upper end of a pump cylinder orwell pip tl. A pump or pistonrod9 is mountedfor reciprocation in the cylinder 18 and has, its upper end 8a suitably connected withasliding cross head I llwhich may be constructed inthe form .of a ,solid bar having vertical slide bearings drilled therein in its end port-ions for reciprocation upon;a'.-pair-,of rigid-,.-.vertica1 guiderods: I I,,which:are1afiiXed;at'

2 their lower ends in sockets provided by the base member I. A suitable packing gland I2 is mounted at the top of base I and surroundsthe piston rod 9.

The vertical guide rods are braced andsecured together in parallel, vertical relation at their upper ends by means of a top bar I3 which is vertically drilled to receive the ends of said rod. The two vertical guide rods with the-topbar I3 form an upright standard or frame in which the several parts of the mechanism are mounted. A second stationary bar l4, traverses the vertical rods I I and is rigidly connected therewith invertical alignment with top bar I3.

Top bar I3 has journaled therein, a transverse horizontal stub shaft I5 which has fixed at one end, a driving pinion l6 and-which may berevolved or oscillated by any suitable source of power, as by a motor or a hand crank C, fixed thereto.

The driving pinion I 6 is in constant mesh with a bull gear H which is fixed to a stub shaft I8 journaled in the medial portion of the stationary bar I4. The stub shaft I 8projects through bar I4 and for some distance therebeyondv and is keyed eccentrically to a gear I9 which is disposed on the front and opposite side of the frame or standard from the bull gear. The periphery of the gear I9 is thus disposed eccentrically of the axis of bull gear I! and carries an outwardly and axially projecting pivot pin 20 to whichthe upper end of a connecting link 2| in the formof a heavy, metal bar, is journaled. A driven gear 22 has keyed thereto eccentrically thereof, a ,stub shaft 23 which is journaled in the cross head bar I 0 connected with the upper end ofv the reciprocable piston rod. Gear 22 is of similar diameter and corresponds in number of teeth to the upper gear I9, which is meshed therewith and shaft 23 is connected eccentrically with gear 22 on a similar radius of eccentricity, as the connection between gear I9 and its stub shaft I8. Connecting link 2i is of a length to constantly retain gears I8 and 22 in mesh and is-journaled at its lower end on a heavy pivot pin- 2'4j disposed axially of gear 22 .and journaled in a' suitable bearing drilled in the lower end of said link.

Operation When the bull gear I! is revolved or oscillated through the eccentrically connected driving gear I9 is progressed from the position shown in Fig. 1 to the position shown in. Fig. 3 and being intermeshed with the companiongearjZ eccentrically journaled on the vertical, slidable cross tudinally of the piston. In this connection, it

will be noted that the axes of stub shafts l8 and 23 which eccentrically journal the companion gears I9 and 22 to the fixed bars M and slidable cross head. respectively, extend in parallel relation in a common vertical plane which is coincident with the axis of piston rod 9. It will further be seen that the application of force and power to the reciprocable member, both in'downward and upward strokes, is progressive and is smoothly accomplished without any jerkiness or marked pulsation, since the companion gears 19 and 22 are in constant mesh and since torque and ccentric principles are utilized rather than lever principles. Link 2| simply acts as a connection medium between the axes of the companion gears 19 and 22 serving to maintain said gears in mesh throughout the entire operation of the jack and in the upward or outward stroke of the plunger, transmitting the lift' from the upper gear 59.

From the foregoing description, it will be noted that I have provided an exceedingly compact, powerful and highly efficient jack for reciprocating pump rods and other longitudinal elements.

With my novel structure, it will be noted that a double eccentric action is obtained through the interrelation of the two eccentrically mounted gears I9 and 22 and their intermeshed and link. connection relation. Thus, the total reciprocat ing stroke obtained instead of being twice the radius of eccentricity of the mounting of one of the gears is nearly four times that radius. This multiplication of eccentricity resulting in a longer stroke is obtained without materiall increasing the over-all housing space required and without materially increasing the power required.

It will further be seen that in the specific form illustrated, my structure lends itself to special attachment for Well casings or cylinders with the base of the structure constituting a closure cap for the cylinder and with the guide rods ll also r constituting longitudinal members of the supporting frame. The several bars l3, l4 and H3 are interchangeable with the exception that in the case of the stationary bars l3 and I4, suitable means must be provided for rigidly securing the same to the appropriate portions of the up standing guide rods ll, whereas the cross head or slidable carriage Ill must smoothly and loosely fit the said rods.

It will of course, be understood that various changes may be made in the form, details, arrangement and proportions of the parts without department from the scope of my invention.

What I claim is:

1. A jack comprising a rotary member adapted to be connected for driving with either a source of rotary or oscillatory power, said rotary member having an axial shaft, a stationary member wherein said shaft is journaled, a power-converting gear wheel eccentrically affixed to said axial shaft and having an axially disposed pivot pin, a reciprocable member adapted to be connected to a longitudinally movable element to be driven, a stub shaft journaled in said reciprocable member and disposed parallel with the axial shaft of said rotary member, a second gear wheel of similar diameter to said first mentioned gear wheel having its teeth in mesh with the teeth of said first gear wheel and fixed eccentrically to said stub shaft on a radius of eccentricity similar to that of said first gear wheel and a connecting link between said two gear wheels journaled at one end upon the axial pivot pin of said first gear wheel and journaled at its opposite end on an axial pivot pin affixed to said second gear wheel.

2. The structure set forth in claim 1, wherein the axis of said first mentioned rotary member and said stub shaft lie in a common plane substantially coincident with the approximate center of said reciprocable member.

3. A jack comprising a rotary member adapted to be connected for driving with either a source of rotary or oscillatory power, said rotary member having an axial shaft, a frame having a bearing in which said axial shaft is journaled, a power converting gear wheel eccentrically aifixed to said axial shaft and having an axial pivot pin affixed thereto, a reciprocable member adapted to be connected to a longitudinally movable element to be driven, said frame having guides for said reciprocated member, a stub shaft journaled in said reciprocable member and disposed parallel with the axial shaft of said first mentioned rotary member, a second gear wheel of similar diameter to said first mentioned gear wheel having its teeth in mesh with the teeth of said first gear wheel and fixed eccentrically to said stub shaft on a radius of eccentricity similar to that of said first gear wheel and a connecting link between said two gear wheels journaled at one end upon the axial pivot pin fixed to said first mentioned wheel and journaled at its opposite end 'on an axially disposed pin fixed to said second wheel,

4. A jack having in combination a rigid frame comprising a pair of parallel guides, a reciprocating carriage mounted in said guides and adapted to be connected with a longitudinally movable element, a stub shaft journaled in said reciprocable carriage, a gear wheel eccentrically affixed to said stub shaft and having its body disposed perpendicularly to said shaft, a second stub shaft journaled in said frame at a point spaced outwardly of said first mentioned stub shaft with the axes of said shafts extending in a common plane disposed parallel with said guides, a second gear wheel affixed eccentrically to said second shaft and of similar diameter to said first gear wheel and intermeshed therewith, a link pivotally connected at one end to the axial portion of said first gear wheel'and pivotally connected at its opposite end to the axial portion of said second gear wheel and means for driving said last mentioned shaft.

5. In combination with a cylindrical member having a longitudinally reciprocable element mounted therein, a jack having in combination a combined base and cap member secured'axially to one end of said cylindrical member, apair of parallel guides rigidly afiixed at their ends to said base, a reciprocating carriage mounted in said guides and adapted to be connected with said longitudinally reciprocable element, a stub shaft journaled in said reciprocating carriage, a gear wheel eccentrically afiixed to said stub shaft and having its body disposed perpendicularly to said shaft, said base and guides constituting portions of a rigid frame, a second stub shaft journaled in said frame at a point spaced outwardly of said first mentioned stub shaft with the axes of said shafts extending in a common plane disposed 5 6 parallel with said guides, a second gear wheel REFERENCES CITED "aflixed eccentrically to said second stub shaft and of Similar diameter to said fir t gear wheel and The foliowmg references are of record in the intermeshed therewith, a link pivotally connected file of thls patent: at one end to the axial portion of said first gear 5 UNITED STATES PATENTS wheel and pivotally connected at its opposite end Number Name Date to the axial portlon of said second gear wheel and 1,205,895 Hoyt Nov. 21) 1916 means for driving said last mentioned shaft.

6. The structure set forth in claim 5 and a bull w FOREIGN PATENTS gear aflixed to said second stub shaft and means Number Country Date for driving said bull gear.

ROSS T CRUIKSHANK 590,490 Germany Mar. 11, 1931 

